Patterson-Kelley MACH Series Installation & Owner's Manual page 30

MACH® Series Gas-Fired Boiler
Low Fire Setting
Set boiler to the "Test Mode Low", as described
above, to achieve minimum firing rate of the boiler.
Check combustion readings using a combustion
analyzer. If combustion readings are not in
accordance with Table 3-1 adjust as follows:
•
Using a 2 mm hex wrench, adjust the pressure
regulator offset adjustment (see the figure below,
item "R") to achieve the CO
in Table 3-1. Note that equal adjustments must be
made to each of the valves. Adjustments to the
offset pressure regulators should not exceed ¼ turn
at a time before allowing the readings to respond
and stabilize. Please note, the rotation of the Low
Fire adjustment is opposite of the High Fire as
follows: Clockwise rotation increases gas flow,
counterclockwise rotation decreases gas flow.
/O level prescribed
2 2
Page 26
Installation
"R"
"D"
Adjusting Low and High Fire